/* GStreamer * Copyright (C) 1999 Erik Walthinsen * PCM - A-Law conversion * Copyright (C) 2000 by Abramo Bagnara * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ #include #include "alaw-decode.h" extern GstPadTemplate *alawdec_src_template, *alawdec_sink_template; /* elementfactory information */ static GstElementDetails alawdec_details = { "A Law to PCM conversion", "Codec/Audio/Decoder", "Convert 8bit A law to 16bit PCM", "Zaheer Merali " }; /* Stereo signals and args */ enum { /* FILL ME */ LAST_SIGNAL }; enum { ARG_0 }; static void gst_alawdec_class_init (GstALawDecClass *klass); static void gst_alawdec_base_init (GstALawDecClass *klass); static void gst_alawdec_init (GstALawDec *alawdec); static void gst_alawdec_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec); static void gst_alawdec_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec); static void gst_alawdec_chain (GstPad *pad, GstData *_data); static GstElementClass *parent_class = NULL; /*static guint gst_stereo_signals[LAST_SIGNAL] = { 0 }; */ /* * alaw_to_s16() - Convert an A-law value to 16-bit linear PCM * */ static gint alaw_to_s16(guint8 a_val) { gint t; gint seg; a_val ^= 0x55; t = a_val & 0x7f; if (t < 16) t = (t << 4) + 8; else { seg = (t >> 4) & 0x07; t = ((t & 0x0f) << 4) + 0x108; t <<= seg -1; } return ((a_val & 0x80) ? t : -t); } static GstPadLinkReturn alawdec_link (GstPad *pad, GstCaps *caps) { GstCaps* tempcaps; gint rate, channels; GstALawDec* alawdec = GST_ALAWDEC (GST_OBJECT_PARENT (pad)); if (!GST_CAPS_IS_FIXED (caps)) return GST_PAD_LINK_DELAYED; if (!gst_caps_get (caps, "rate", &rate, "channels", &channels, NULL)) return GST_PAD_LINK_DELAYED; tempcaps = GST_CAPS_NEW ( "alawdec_src_caps", "audio/x-raw-int", "depth", GST_PROPS_INT (16), "width", GST_PROPS_INT (16), "signed", GST_PROPS_BOOLEAN (TRUE), "endianness", GST_PROPS_INT (G_BYTE_ORDER), "rate", GST_PROPS_INT (rate), "channels", GST_PROPS_INT (channels), NULL); return gst_pad_try_set_caps (alawdec->srcpad, tempcaps); } GType gst_alawdec_get_type(void) { static GType alawdec_type = 0; if (!alawdec_type) { static const GTypeInfo alawdec_info = { sizeof(GstALawDecClass), (GBaseInitFunc)gst_alawdec_base_init, NULL, (GClassInitFunc)gst_alawdec_class_init, NULL, NULL, sizeof(GstALawDec), 0, (GInstanceInitFunc)gst_alawdec_init, }; alawdec_type = g_type_register_static(GST_TYPE_ELEMENT, "GstALawDec", &alawdec_info, 0); } return alawdec_type; } static void gst_alawdec_base_init (GstALawDecClass *klass) { GstElementClass *element_class = GST_ELEMENT_CLASS (klass); gst_element_class_add_pad_template (element_class, alawdec_src_template); gst_element_class_add_pad_template (element_class, alawdec_sink_template); gst_element_class_set_details (element_class, &alawdec_details); } static void gst_alawdec_class_init (GstALawDecClass *klass) { GObjectClass *gobject_class; GstElementClass *gstelement_class; gobject_class = (GObjectClass*)klass; gstelement_class = (GstElementClass*)klass; parent_class = g_type_class_ref(GST_TYPE_ELEMENT); gobject_class->set_property = gst_alawdec_set_property; gobject_class->get_property = gst_alawdec_get_property; } static void gst_alawdec_init (GstALawDec *alawdec) { alawdec->sinkpad = gst_pad_new_from_template(alawdec_sink_template,"sink"); alawdec->srcpad = gst_pad_new_from_template(alawdec_src_template,"src"); gst_pad_set_link_function(alawdec->sinkpad, alawdec_link); gst_element_add_pad(GST_ELEMENT(alawdec),alawdec->sinkpad); gst_pad_set_chain_function(alawdec->sinkpad,gst_alawdec_chain); gst_element_add_pad(GST_ELEMENT(alawdec),alawdec->srcpad); } static void gst_alawdec_chain (GstPad *pad,GstData *_data) { GstBuffer *buf = GST_BUFFER (_data); GstALawDec *alawdec; gint16 *linear_data; guint8 *alaw_data; GstBuffer* outbuf; gint i; g_return_if_fail(pad != NULL); g_return_if_fail(GST_IS_PAD(pad)); g_return_if_fail(buf != NULL); alawdec = GST_ALAWDEC(GST_OBJECT_PARENT (pad)); g_return_if_fail(alawdec != NULL); g_return_if_fail(GST_IS_ALAWDEC(alawdec)); alaw_data = (guint8 *)GST_BUFFER_DATA(buf); outbuf=gst_buffer_new(); GST_BUFFER_DATA(outbuf) = (gchar*)g_new(gint16,GST_BUFFER_SIZE(buf)); GST_BUFFER_SIZE(outbuf) = GST_BUFFER_SIZE(buf)*2; linear_data = (gint16*)GST_BUFFER_DATA(outbuf); for (i = 0; i < GST_BUFFER_SIZE(buf); i++) { *linear_data = alaw_to_s16 (*alaw_data); linear_data++; alaw_data++; } gst_buffer_unref(buf); gst_pad_push(alawdec->srcpad,GST_DATA (outbuf)); } static void gst_alawdec_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec) { GstALawDec *alawdec; /* it's not null if we got it, but it might not be ours */ g_return_if_fail(GST_IS_ALAWDEC(object)); alawdec = GST_ALAWDEC(object); switch (prop_id) { default: break; } } static void gst_alawdec_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec) { GstALawDec *alawdec; /* it's not null if we got it, but it might not be ours */ g_return_if_fail(GST_IS_ALAWDEC(object)); alawdec = GST_ALAWDEC(object); switch (prop_id) { default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } }